Blower wheel



Jan. 27, 1959 Filed Nov. 7, 1956 W. A. GIDDINGS BLOWER WHEEL BY M. M

2 Sheets-Sheet 1 INVENTOR WAYNE A. GIDDINGS ATTORNEY Jan. 27, 1959 W.GIDDINGS BLOWER WHEEL 2 Sheets-Sheet 2 INVENTOR WAYNE A. eloomes BY M MATTORNEY Filed Nov. 7, 1956 2 2 m B Sm 5:5.lain!-liiiii\\iii\\\\\\\\ \n.3 z m W In 8 3 3 J 3 a 9 II 2 4 I J. 5 5 3 6 a a 3 wheel.

United States Patent 2,870,959 BLOWER WHEEL Wayne A. G-iddings, CedarRapids, Iowa, assignor to Amana Refrigeration, Inc., Amana, Iowa, acorporation of Iowa This invention generally relates to fans and moreparticularly to an improved type of centrifugal fan or blower In theconstruction of such items as freezers and refrigerator's in which themachine. compartment is included within a single cabinet it is notuncommon to be limited in the overall dimension of the unit to theextent that sufiicient space for air flow and a means to effeet the heattransfer to the exterior of the unit becomes a problem. This isparticularly true for built-in freezers and built-in refrigerators. Whenthe heat transfer surface is comparatively small it is necessary to haveincreased air flow to carrythe heat to the exterior of the unit. In thiseffort to conserve space and to providea sufficient amount of air flowover the heat transfer surface, the blower wheel disclosed inthisapplication was invented.

This blower wheel is constructed to provide a maxi- I mum amount of airflow in comparison to its size and. the amount of space which itoccupies. The blower wheel is light, rigid yet resilient, so that it iseasyto assemble and needs no later adjustment because of bent blades orfins. source that vibration is not a problem and the blower wheel doesnot need to be balanced to provide a smooth performance. It p'atentablydeparts from the conventional, is unique, and incorporates manydesirable features and characteristics over the prior art. Many factorswere considered among which were the ease of manufacture, the cost ofmaterials, shipping costs, assembly cost, ease of assembly, andreduction in service costs at a later date.

It is therefore an object of the present invention to It is so light incomparison to the power Patented Jan. 27, 1959 Figure 2, is a sectionalview taken on line II-II of Figure 1;

Figure 3 is a rear elevation of the blower wheel;

Figure 4 is a cross-section of a blade taken on line IVIV of Figure 1;

Figure 5 is a sectional view of a blade V-V of Figure 1;

Figure 6 is a front elevation of my fluid impeller including the scrolland the power source.

As shown in the drawings:

The blower wheel 10 comprises a substantially flat planar disc or base11 and a series of fins or blades 12 extending perpendicularlytherefrom. The base 11 is of circular configuration and is made ofaluminum or other suitable light material. There is an embossment 13 inthe center of the base 11 and a circumferential fiat annulus 14 betweenthe periphery 15 of the embossment and the outer periphery 16 of thebase 11. There are five holes 17 in the center of the basefor mountingpurposes and two additional holes 18 in the annulus 14 which areutilizedin positioning the base 11 in the mold during the manufacturing process;There are also a number of equally spaced radial slots 19 in the annulus 14 which are in spaced relation to the outer pe riphery16.

Each fin or blade 12 coincides with a radial slot and extends through itwith reinforcing flanges 20 and 21 on either side of the base 11. Eachblade 12 extends perpendicularly from the plane of the annulus 14 andtaken on line as best shown in Figure 5 is tapered, becoming narrower36) of the base 11 and the outside reinforcing ring 28 provide a blowerwheel which has increased efficiency in the movement of air and also inthe reduction of noise caused by air flow.

Another object of this invention is to provide a blower wheel which isof light weight in comparison to its power source to the extent thatvibrations are minimized or non-existent because of the relativedifferences in the masses of the blower wheel and power source.

Yet another object is to provide a blower wheel which is easily andsimply manufactured.

Still another object of this invention is to provide a blower wheelconstructed of two dissimilar materials thereby providing a rigid yet aresilient construction.

Yet another object is to provide a fluid impeller in which the rotatingblades extend both within and without a stationary scroll.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein the preferred form of the invention is clearly shownfor purposes of illustration only.

In the drawings:

Figure 1 is a front elevation of my invention with a portion partiallybroken away;

completely encompasses the outer periphery 16. It completely surroundsthe annulus 14 and protrudes on both sides of it. The blades 12, thereinforcing rings 27 and 28, the reinforcing flanges 2i) and 21, thefillets 23, 'and the reinforcing rib 25 are all integral and are moldedto the base 11 in the manufacturing process. This blade and reinforcingstructure is preferably made of a synthetic material which is rigid, yetself-supporting, and is sufficiently resilient to absorb shock. Inaddition, it should also have good characteristics in the resistance toheat. One of thereasons for not having the entire fan manufactured froma synthetic material is because of the danger of the plastic materialmelting should the motor be in a locked rotor condition. The heat fromthe power source is much better dissipated through a metal base 11.

When the fan is manufactured the base 11 is prefabricated and ispositioned in a mold by means of the two holes 18 previously mentioned.The mold is gated at four places and the synthetic material introducedunder suihcient temperature and pressure to cause flow and filling ofall cavities. In addition to the reinforcing advantages of the rings 27andZE and the flanges 20 and 21 their mold cavities also serve asconduits for the even flow and distribution of synthetic material withinthe mold. As the molten plastic is cooled both the reinforcing rings 27and 28 contract, thus snugging the entire vane structure radially towardthe center of the disc 11. This same effect also takes place in therebase 11. Thus, the vanes or blades 12 are molded and maintained in afixed position in each individual slot and integral throughout. It isalso to be noted that in addition to the structural advantage of atapered blade and fillet 23 this feature also expedites the ejection ofthe completed blower wheel from the mold.

In assembly for operation the blower wheel 10- is attached to a powersource 32 and is placed within a scroll 33. As shown in Figure 6 thepower source 32, the blower wheel 10 and a combination spider leg motormountz34 and inlet eye 35 are previously assembled before attaching tothe scroll- 33. When completely assembled the unit is inserted intoscroll 33 and secured therein by means of screws 36. This constructionis further illustrated in Figure 2 where it is readily seen that theblower wheel 10, having a smaller diameter, may be takenfrom the scroll33 when the inlet eye 35 is removed. Also as. shown in. Figure 2 thefins 12 extend partially beyond the scroll 33 and are radiallypositioned around the power source 32. In addition to cooling the powersource, this also provides for an increased. amount of air flow which isessential in removing the heat to the exterior of a. refrigerating unitwhen only a limited heat transfer surface is used.

Although the invention has been described with considerable.particularity in connection with the illustrated embodiment, it is to beunderstood that the invention is not limited to the details ofconstruction or to the specific relations of. parts described, as manymodifications will: readily occur to those skilled in the art, and allsuch. modifications as. come within the scope of the appended claims andtheir equivalents are to be considered as being. within. the invention.

I claim as my invention:

. 1. In a blower wheel, a circular metallic base plate provided withcircumferentially spaced radial slots, and a. molded integral bladestructure mounted on said base plate comprising blades disposed radiallyof said plate and having base portions extending through said slots withbase flanges engaging the opposite faces of said plate, saidbladesprojecting upwardly from'said plate substantially parallel with the axisthereof and tapering in thickness upward, a continuous outer reinforcingring connecting the bases of all of said blades and enclosing the outercircumferential portion of said plate, and a continuous inner ringconnecting. the bases of all of said blades. at the upper face of saidplate.

2. In a blower wheel, a circular metallic base plate 4 provided withcircumferentially spaced radial slots, an a molded integral bladestructure mounted on said base plate comprising blades disposed radiallyof said plate and having base portions extending through said slots withbase flanges engaging the opposite faces of said plate, said bladesprojecting upwardly from said plate substantially parallel with the axisthereof and tapering in thickness upward, said blades having at theirradially inner edges angularly disposed lengthwise reinforcing ribs, acontinuous outer reinforcing ring connecting the bases of all of saidblades and enclosing the outer circumferential portion of said plate,and a continuous inner ring connecting. the bases of all of said bladesat the upper face of said plate.

3. In a blower wheel, a circular metallic base plate provided withcircumferentialy spaced radial slots, and a molded integral bladestructure mounted on said base plate comprising blades disposedradiallyof said plate and" havingbase portions extending through said slots withbase flanges engaging the opposite faces of said plate, saidbladesprojecting upwardly from saidplate substantially parallel with the axisthereof andtapering in thickness upward, said blades having at theirradially inner edges angularly' disposed lengthwise reinforcing. ribsand being provided at their radially outer edges with substantiallyrectangular cutouts extending from their upper ends, a continuous outerreinforcing ringconnecting the bases of all of said blades and enclosingthe outer circumferential portion of said plate, and a continuousv innerring connecting the bases of all of said blades at the upper face ofsaid plate.

References Cited in the file of this. patent UNITED STATES PATENTS1,035,364 Le Blane Aug. 13, 1912 1,128,854 Coppus Feb. 16', 1915'1,832,899 Frederics Nov. 24, 1931 2,101,123 Wyche Dec. 7, 1937 2,237,451Samuels Apr. 8 1941" 2,297,309 Limbel't Sept. 29, 1942 2,443,411- WolfeJune 15, 1948 2,621,369 Gantz et al. Dec. 16, 1952 2,734,457 FernstrumFeb. 14, 1956 FOREIGN PATENTS 623,149 Great Britain May 12', 1949

